I had an occurrence yesterday when after trying to connect to a WiFi network with a hidden SSID and no password, all preexisting WiFi networks got wiped from my Glo, and I was unable to successfully add any new ones.
While YES I could scan and add one, it was never added to the list of known networks.
Prior to doing a factory reset I decided to make a new "empty" wpa_supplicant.conf file (well not exactly empty; it contained a copy of wpa_supplicant_conf.template), place it in a KoboRoot.tgz file and load that onto the Glo.
TADA
SUCCESS
Contents of /etc/wpa_supplicant/wpa_supplicsnt.conf
Code:
ctrl_interface=/var/run/wpa_supplicant
update_config=1